Motor drill for oil well casings and the like



Dec. 26, 1939. H. R. SHARP 2,184,817

MOTOR DRILL FOR OIL WELL CASINGS AND THE LIKE Filed April 14, 19:59 2Sheets-Sheet 1 Inventor I32. Ska? Dec. 26,1939. H. R. SHARP 4,817

MOTOR DRILL FOR OIL WELL CASINGS AND THE LIKE Filed April 14 1959 1 2Sheets-Sheet 2 x-fn? In venior 5&0? M

A ttnrneus Patented Dec. 26, 1939 UNITED S ATES MOTOR DRILL FOR OIL WELLOASINGS AND THE LIKE Harold R. Sharp, Waterloo, Iowa, assignor ofonehalf to Ray M. Sharp, Waterloo, Iowa Application April 14,1939,Serial No. 267,889

1 Claim. (01. 255-4) This invention relates to a' well boring device,the general object of the invention being to provide means for boringthe well in such a manner that it can be cased as the boring proceeds asthe cutting means are so formed as to make a hole of greater diameterthan the casing, said cutting means contracting to permit the boringmeans to be removed from the casing without Pulling the casing.

Another object of the invention is to provide an enclosed electric motorfor driving the shaft which carries the expansible and contractiblecuttingfmeans, with means for guiding the enclosed motor by a bottom"casing section. Another object of the invention is to provide means forcooling the motor assembly by fluid which is circulated through the wellto remove the cuttings therefrom.

-This invention also consists in certain other features of constructionand in the combination and arrangement of the several parts to behereinafter fully described, illustrated in the accompanying drawingsand specifically pointed out in the appended claim., In describing theinvention in detail, reference will be had to the accompanying drawingswherein like characters denote like or corresponding parts throughoutthe several views, and in which: Figure 1 is a view showing the lowersection of a well casing in longitudinal section and the drillingassembly in elevation.

Figure 2 is a bottom plan view of the drill head. a

Figure 3 is a longitudinal sectional view. through the upper portion ofthe motor assembly. Figure 4 is a similar view \through the lowerportion of the motor assembly.

Figure 5 is a section on the line 55' of Figure In these drawings thenumeral I indicates a lower section of a we1l casing, said section beingprovided with the interior vertically arranged guides 2 and the numeral3 indicates a housing of a motor assembly which is provided withlongitudinally extending ribs 4 for engaging the guiding means 2 so thatthe housing is supported for sliding movement in the housing i and isheld against turning movement therein. An electric motor is located inthe casing 5 which is 60 supported in spaced relation in the casing 3 bythe lugs 6, the motor including the fields 'I and the armature 8attached to the shaft 9, The shaft is provided with the anti-frictionbearing means shown generally at III in the upper part I. of the casing5 and. a similar bearing means II in the lower part of the said casingand upper and lower packing means l2 are associated with each bearingmeans so as to prevent any liquid or moisture entering the casing 5. Theupper end of the casing 5 is closed by a cap l3 and a 5 conical member Iis fastened to the cap l3 and a conical cap I5 is threaded to the upperend of the housing 3 and has a threaded reduced cylindrical end l6 forreceiving the lower end of a. tube line which is used to introducefluid, 0 such as drilling mud into the housing 3. This fluid is directedby the conical part It into the space between the casing 5 and housing3, the fluid passing through said space and escaping at the bottom ofthe well and then this fluid 15 passesupwardly between the housing 3 andthe casing l to the top of the well. The lower end of the shaft passesthrough a cap or cover plate I! inthe bottom of the casing 5 and anannular collar l8 and a cup-shaped member l9 are fas- 20 tened to thecap I1 by the bolt 20: The inner circumference of the member It forms aconical ball race for the anti-friction means 2| and a stub shaft 22passes through the lbwer end of the member l9- and has a cup-shaped part23 25 on its upper end which fits over the lower end of the shaft 9 andis slidably connected with the said lower end ofthe shaft 9 by means ofthe key member 24 fastened to the lower end of the shaft 9 and havingits teeth engaging key- 30 ways in the member 23. The upper end of themember 23 forms a conical ball race and the anti-friction means 2i areheld between this ball race and the race formed by the innercircumference of the member l8. 35

A drill head 26 is fastened to the lower end of the stub shaft 22 andisformed with the slots 21 in its lower face in which are locatedportions of the elongated bar-like bits 28, each of which has its innerend pivoted to the head 26 as shown 40 at'29. While the drawings showtwo of these hits it will now be understood that as many bits can beused as are necessary or desired.

As will be seen the stub shaft 22 which carries the drilling means haslimited sliding movement 45 on the motor 'shaft 9 and this movement isresisted by the anti-friction means 2| and thus strain on the 'motorshaft 9 is relieved. The current for the electric motor is conducted tothe same by suitable conductors passing through a cable, a portion ofwhich is shown at 30.

As will be seen the section I of the well casin will prevent rotarymovement of the housing 3 while permitting the said housing to be movedvertically. The bits or cutters 28 when expanded by resting on thebottom of the well will cut a hole of greater diameter than the diameterof the casing l.so that the casing can be fed downwardly as the holeisbeing bored, it being understood that the section I is moveddownwardly.

as the well is being bored and other sections are placed on the top ofthe section I as the depth of the well increases, all the sectionsremaining in place after the boring has been completed. Pressure isapplied to the motor assembly and therefore to the cutting means throughmeans of the tubing connected with the nipple l6 and used for feedingfluid into the device. As before stated this fluid will pass between thehousing 3, and

casing 5 and will flow into the bottom of the well and then passupwardly between the housing 3 and casing l, dislodging the cuttingsfrom the well. Any time that it is desired or necessary the housing 3with the parts associated there with can be removed for as soon as themember 3 is lifted the bits will drop so that they can pass through thecasing I and, of course, the

member 3 can be inserted into the casing I by having the bits swingdownwardly so that they will pass through said casing i. As soon as thedrill head hits the bottom of the well the bits or cutting members 28will swing outwardly and thus cut a hole of greater diameter than thediameter of the well casing.

It is thought from the foregoing description that the advantages andnovel features of the invention will be readily apparent.

It is to be understood that changes may be made in the construction andin the combination and arrangement of the several parts provided thatsuch changes fall within the scope of the appended claim.

casing in the housing and spaced therefrom to form a passage betweenitself and the housing for the passage of the said liquid, an electricmotor in the casing, means for closing the ends of the casing in aliquid-tight manner, antifriction means for the shaft of the motor, ashaft' section extending from the lower end of the motor casing, meansfor slidably connecting said shaft section with the motor shaft, athrust bearing at the upper end of the shaft section,'a head 1' on theshaft, cutting means carried by the head for cutting a hole of greaterdiameterthan the casing section, means whereby said cutting means I willmove downwardly and inwardly when the head is lifted off the bottom ofthe well to permit the cutting means to pass through the well casing.the liquid introduced into the housing flowing through said passage intothe bottom of the well and then passing upwardly between the housing andthe well casing.

HAROLD R. SHARP.

